It was a long way away from any Hollywood red carpet at Saturday's Sarajevo Film Festival in Bosnia -- making it the perfect event for Angelina Jolie to publicly debut her gigantic engagement ring from Brad Pitt.

The "Maleficent" actress, 37, was first seen wearing the $500,000, tablet-shaped rock (co-designed by jeweler Robert Procop and Pitt, 48) in early April during a private viewing at the Los Angeles County Museum of Art's Chinese Galleries. When an intrepid photographer snapped the bauble, Pitt's manager confirmed the long-awaited engagement to the world.

Named an Honorary Citizen of Sarajev, Jolie spoke with young actors, directors, screenwriters, producers and film critics from the region about her own writing and directorial debut, the dark Bosnian War romance "In the Land of Blood and Honey."

The students, one attendee tells Us, were "impressed." When asked about her humanitarian work -- Jolie is now a Special Envoy for the UNHCR -- she explained that she "wants to give something back to underprivileged people," the attendee added.

On Saturday afternoon, Jolie was spotted arriving at her hotel with daughter Shiloh, 6; the star and Pitt and their brood of six have been staying in London while she shoots "Maleficent" at Pinewood Studios.

As for that wedding?

"We actually, really and truly, have no date," Pitt, 48, said at Cannes in May.

"It's just something that makes sense to us, and certainly date-wise, it's just a rumor," he continued. "We're still hoping that we can figure out marriage equality in the states before that date."